Electric meter.



17 H. PRATT.

ELECTRIC M APPLICATION FILED AYE. no, 1:104,

'ZTER.

Patented Feb. 14, 1911.

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W. H. PRATT. ELECTRIC METER.

APPLICATION FILED APILZO, 1904. 984,297. Patented Feb. 14,1911

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984,297. Patented Feb. 14, 1911 3 $HEETB-BHEET 3.

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Wi messes Irv/ember:

William H. Pratt, I

@YWW $1M 9? UNITED STATES BliflENT OFFICE.

WILLIAM H. PRATT, 0F LYNN, MASSACHUSETTS, ASSIGNOR T0 GENERAL ELECTRICCOMPANY, A CORPORATION OF NEW YORK.

. ELECTRIC METER.

Specification of Letters Patent. Patenfied'lieb, 14, 1911 Applicationfiled April 20, 1904. Serial No. 204,060.

To all whom it may concern: is supported in the usual manner on jewel itknown that l, \VILLIAM H. Pulvr'r, a bearings carried by the member A.The staeitizen of the United States, residing at tionary magneticcircuit consists of two Lynn, county of Essex, and State ofMassalaminated cores C and C secured to member chusetts, have inventedcertain new and use- A by the boltsm. Ihe arrangement of the t'ulImprovements in Electric Meters, of magnetic circuit and its coils willbest be whiclrthe following isa specification. understood by referenceto Fig. 5. In this My invention relates to alternating-cmtigurc, core Cis shown as comprising a cenrent induction meters, and its object totral member on which is wound the potenprovide a wattmeter of simple andconnjiacttial coil I and two parallel portions, each construction, whichwill operate. etliciently of which nearly completes the magnetic cirandaccurately on varying loads and power cuit of the central member,thereby lagging, factors. the current in coil I in the manner well Onefeature of my invention consists in understood in the art. In otherwords, the a novel management of magnetic circuit, core C is ol arectangular shape having a \vlierel'iy a high torque and proper phasecentral member on which is wound a polar displacement are secured.forall loads and tial coil. the rectangle helm;- interrupted by powerfactors. I a small air-gap at. each side of one end of Another featureof my invention consists the central core. The core C is of a U- of anovel form of means for counterbalauc shape, each of its poles facingone of the ing' the starting friction. air-gaps in core C. and eachcarrying there- .\nolher feature of my invention consists on a seriescoil S. The disk. which is not in a novel arrangement oi the magneticshown in this figure. is disposed between the shield between the motiveparts of the meter two cores (l and The leakage flux of and the dragl'nechanism and of the other coil l". which does not Pass across the airparts of the meter, whereby a compact strucgaps and through the nearlyclosed anagture is secured. uetic circuit of core (1 passes through theOther :l'eatures of my invention will apdisk to the poles ol core C. Thecoils S S pear from the following specification and are oppositely woundand produce fluxes accoinpauyiundrawings, in which--- which. with theleakage flux of coil P, prol igure 1 shows a front elevation of a meterarranged in accordance with my in veution, the front. cover beingremoved; Fig. 2 shows a plan view of the same, the top casing: beingremoved; Fig. 3 shows a side elevation in cross-section: Fig. shows aback view. the back cover being removed; Fig. 5 is a diagrammaticrepresentation of themagnetic circuits; Fig. 0 shows a modification oithe same; and Fig. 7 shows a further modification.

1n the drawings, A represents the back portion of the casing providedwith lugs a for attaching the meter toits support.

A represents a second portion of the cusing which is secured to the backcover A by means of the screws 0.

A represents the front cover of the meter which is secured to the memberA by the bolts I The motive part of the meter comprises the movablearn'iature I), which consists of the usual conducting disk, and thestationar magnetic circuit with its energizin 0011s. Disk D is carriedby shaft d, whic quent rotation of the disk in a manner well umlerstoodin the art. eircuited through the resistance ll, is n1ounted on the endoi the central member of core (l. and is traversed by the potentialleakage .llux. which passes from the central member through the disk.and thereby produces the 00 degree displacement oi the potential [butthri'iugh the disk in the manner well understood in the art. By varyingthe resistance ll. the client of coil L may be adjusted. It will be seen-from the drawings that the series coils have a nearly closed magneticcir- -euit. and accordingly exert a strong torque.

in the arrangement of Fig. 6 the poles on core C on each side of each ofthe air-gaps are extended, and a portion of the series In thearrangement of Fig. 7 the core C of Fig. 6 is duplicated, the secondcore C taking the place of the core C.

In order to compensate for thestarting friction, I provide the movablemember E, which is suspended directly above the disk duce a shiftingresultant flux and conse The coil L, short winding is placed on theseextended poles.

gaps and adjustable in a direction approximately parallel to the planeof the disk.

6. In an alternating-current meter, a magnetic shield, a rotatable disksupported thereby, motive elements adapted to drive said disk supportedfrom one side of said shield, and drag magnets supported from the otherside of said shield.

'7. In, an alternating-current meter, a mag netic shield forming part ofthe meter casing, a rotatable disk supported thereby, motive elementsadapted to drive said disk supported from one side of said shield, anddrag magnets supported from the other side of said shield.

8. In a meter, a base portion, a member removably secured thereto andforming a partition of magnetic material through the meter, a rotatableconducting disk extending tbrough said partition, motive elements fordriving. said disk on one side of said partition, and drag-magnets onthe other side, said disk, motive elements, and draganagnets beingsupported by said partition and removable therewith from the baseportion.

9. In a meter, a base portion, a member removably secured thereto andforming a partition of magnetic material through the meter, a rotatableconducting disk extending through said partition, motive elements fordriving said disk between said parli- [i011 and the base portion, anddrag-magnets and recording means in front of said partition, said disk,motive elements, drag magnets and recording means being supported bysaid partition and removable therewith.

10. In a meter, a lilll(-]')ftl'b casing comprising a base portion, asecond portion adapted to be secured. thereto and forming a partitionthrough the motor, and a third portion adapted to be secured to thesecond portion, and meter elements oporativcly as sociated, someinclosed between the first and second portions and others between thesec ond and third portions of the casing.

11. In a meter, --a three-part casing comprising a base portion, asecond portion ai'la'pted to be secured theretomnd forming a partitionthrough the meter, and a third portion ada )ted to be secured to thesecond portion, an meter elements operativelyassociated, all supportedby said second portion, some between the first and second por-' t-ionsand others between the second and third portions of the casing. 7

12, In a meter, a three-part casing comprising a base portion, a secondportion adapted to be secured thereto and forming a partition ofmagnetic material extending through the meter, and a third portionadapted to be secured to the second portion, a conducting rotatable disksupported by the second portion and extending through the partitionformed thereby, means for driving the disk, and means for retarding thedisk, said driving and retarding means being supported by said secondportion on opposite sides of the partition.

13. An electric meter for use on alternating-circuitscomprising incombination, a series eleetromagnet; a multipolar shuntmagnct; a coilconnected as a shunt across the supply-mains and wound on a part only ofsaid shnnt-n'iagnet whereby considerable magnetic leakage is producedfrom the remaining parts, together with a rotatable clcmcnt mountedbetween said series and said shunt magnets, substantially as described.

[4. An electric meter for use on alternating-circuits comprising incombination, a muitipolar series clcctromagnet: a multipolarshuntanagnet; a coil connected as a shunt across th supplyanains andwound on a part only of said shunt-magnet whereby coushlcrablc magneticleakage is produced from the remaining parts, together with a rotatableelement mounted between said scrios and said shunt magnets,sul'istaiitially as described. I

in witness uluxrcofll have hereunto set my hand this eighteenth day ofApril, 1904.

WILLIAM H. PRATT.

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